Ease of Matching a Load Line Impedance in a 25 W Contiguous Mode Class BJF⁻¹ Broadband Amplifier

We investigate contiguous modes called “the series of continuum modes” (SCM) and class BJF−1 that offer a resistive component of the load line impedance that is 1.17 times and 1.7 times that of class B, respectively. Both these modes result in a similar performance of efficiency, output power, and gain, but class BJF−1 has a wider design space and is easier to match. An increase in the resistive component of the fundamental impedance of class BJF−1 increases efficiency with minimal impact on the bandwidth for an inductive load. An amplifier designed in class BJF−1 using the CGH40025F demonstrates an average efficiency of 70.8% and output power greater than 28 W over a bandwidth from 2.2 to 3.3 GHz, resulting in a comparable frequency weighted efficiency (FE) of 91% with respect to other reported amplifiers with similar fractional bandwidth (FBW) and output power while operating at the highest reported frequency (3.3 GHz) using this device.